As we have discussed, the time scales required to reach the large
deviation asymptotics are too long for the large deviation rate functions
to be relevant to discuss seasonal heat waves or cold spells. However,
the rare event algorithm itself [1]}
does not need \(T_{a}\)  to be in the large deviation asymptotics. In
[2]} we have exploited this property to show how
the algorithm could be used to sample extremely rare heat waves with
return times up to millions of years, with computational costs two
to three orders of magnitude smaller. Here we recall the main results
of [2]}, connecting them more explicitly with the
previous sections.
